Centeifugal ventilatoe



4 Sheets-Sheet 1 PatentedDec. 19, 1893.

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(No-Model.)

1 C. G. HERSGHER.

GENTRIF'UGAL VENTILATOR.

THE uAnouAL LITHOQRAPHING COMPANY.

- (H0 Model.) 4 SheetsSheet 2.

G.G.HERSGHER. GENTBIFUGAL VENTILATOB.

No. 511,140. Patented Dec. 19, 1893.

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C.G.HERSG HER. GENTRIFUGAL VB NTILATOR.

No. 511,140. Patented Dec. 19, 1893.

(No Model.) 4 Sheets-Sheet 4.

C. G. HE'RSOHER. GENTRIFUGAL VBNTILAIOR.

' No. 511,140. Patented 1360.1951893.

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U IT- n;- STATES PATENT QFFIC CHARLES GEORGES HERSOHER, OF PARIS, FRANCE, ASSIGNOR TO THE SOCIETY GENESTE, HERSCHER ET (30., OF SAME PLACE.

CENTRI FUGAL VENTILATO R.

SPECIFICATION forming part of Letters Patent No. 511,140, dated December 19,1893. v

Application filed May 18, 1893. Serial Ila. 474,663. (No model.) Patented in France August 20, 1892, No. 223,848, and in England March 30, 1893,11'0. 6,758.

To all whom it may concern.-

Be it known that I, CHARLES Gaonens HERSOHER, a citizen of the Republic of France, and a resident of Paris, in said Republic, have invented certain new and useful Improvements in Centrifugal Ventilators,

which are fully described in the following specification, and for which I have obtained Letters Patent in France, No. 223,848, dated August 20, 1892, and in Great Britain, No. 6,758, dated March 30, 1893. a This invention relates to a new kind of contrifugal-ventilator in which the organs are so disposed as to obtain the maximum yield in pressure and work. To accomplish this result it is sought in the present invention to eliminate the causes of loss of charge, of eddies, and of shocks during the flow of the air from the inlet of the apparatus to the extremity of the receiving chamber and in particular to avoid, first, contraction of the stream of fluid (the vents conlraca of physicists) at the inlet of the ventilator; second, loss of charge due to the turn between the ventilator inlet and the entrance portions of the channels formed by and between the vanes or floats; third, contraction (who. contractor) atthe entrance portions of the said channels; fourth, eddies at the beginning of the vanes or floats at the ventilatorinlet; fifth, loss of pressure in the passage of the fluid through the channels formed by and between the vanes or floats; sixth, defective guiding of the fluid in said channels; seventh, incomplete utilization of the impellin g velocity at the extremities of thevanesor floats; eighth, unequal distribution of the fluid in the receiving chamher at the ends of the vanes or floats; ninth, shocks of the fluid passing from the channels into the receiving chamber; tenth, friction and shock encountered by thefluid during its passage through the receiving chamber. The dispositions whereby these disadvantages can be avoided in what is considered the best mode, are represented by way of illustration in the accompanying drawings which form part of this specification, and in which- Figure 1, is a vertical section of a blowing ventilator constructed in accordance with the invention. Fig. 2, is a transverse section of the same apparatus. Fig. 3,isa section parallel to the plane of the Wheel of an aspirating and blowing ventilator, also constructed positions adopted severally to remedy the different losses of pressure, eddies and shocks enumerated above.

1; Means of avoiding the contraction (rend cont meta) of the stream at the ventilator 'z'nlcl.'-Contraction at the inlet of the ventilator results in a'diminution 'of pressure corresponding to the square of the dilference of the velocities of the air in respectively the contracted section and the entrances of the movable channels between the vanes or floats. To avoid the effect of such contraction it suffices that the velocity with which the'fluid is animated in its passage through the ventilator inlet be not diminished. To efiect this, a flaring mouth A, Fig. 2, is placed at the ventilator inlet, so that the flow takes place,

not as through an orifice in a thin Wall, nor

even as through a cylindrical pipe, but like that obtained through a pipe of suitable con verging conical form.

2. Dimr'mltion of the loss of charge due to the turn between the rentilator inlet and the entrances of the channels between the names or floals.The air enters the ventilator inlet in the direction perpendicular to that in which it escapes into the receiving chamber. From this change in direction results a loss of pressure which can be avoided by giving a minimum value to the ratio of the cross section of the stream to the radius of curvature of the middle of such stream. Figs. 2 and 4 show the radius of curvature which results from the convexity of the wall at the ventilator inlet.

3. Reduction of contraction, (ocna contractor) at the entrances of the movable chcm- 5 IOC stream which is thus produced in a passage of constant section is similar-to that obtained to avoid this that in the new or improved ventilator the channels are made to decrease in section from the entrances E F to about their middle 0 D, so that the stream produced fills the channel (Fig. 2).

4. Suppression of eddies at the beginning of the vanes or floats at the ventilator inlet- These eddies are avoided by given to the different points of the edge E F of each vane or float, normal to the curve E F representing the direction of the current at the middle'of the stream at the entrance to each channel, an inclination corresponding with the im pelling velocity at each of these points so that the fluid enters over the whole depth of the vane or float without shock. To this end the part G H of the vane or float (the latter mounted on a central disk M M) is given a form corresponding with the surface of an oblique cone of circular section whose generatrix,'wh-ich has its path at H, Fig. 1, is per pendicular to the plane of the wheel. Besides the anglev of the cone is so chosen that each of-the points receives the fluid under a variable angle decreasing in proportion toits distance from the center of the wheel. As moreover, the vane or float at its partH I is bentto conform to a cylindrical surface normal .to the disk supporting the vanes or floats, it results that the entire vane or float is capable of development on a plane, which capacity contributesto the simplicity of its construction. It isnot intended to limit the invention-to the combination of a cylindrical surface with a conical curvature of.the vane orfloat, but it extends to surfaces capable of development of a plane in general aside from the, employment of simple cylindrical curvature.

5. Diminution of the losses of pressure of the, air during its passage through the channelsformed by the vanes or fl0ats.This result is obtained on the one hand by so shaping the channels that the current at the. middle of the stream in each channel has a path of a great radius of curvature which becomes greater toward the exit, or end of the channel, and upon the other hand by limiting the 1 section of the channelsformed by the vanes or floatsto the smallest perimeter, a result obtained by proportioning the height and width of the channels.

6. Guiding of the fluid in the channels and the float or vane without having acquired the absolute velocity which it is desired to give it. To overcome this difflculty it is necessary on the one hand that the length of the channel be proportioned to its width so that the streams of fluid cannot escape without being deflected longitudinally of the floats or vanes and on the other hand that the end portions of the channels have also a sufficient length for securing the delivery of the fluid at the angle desired. This has been effected in the new and improved ventilator by the disposition givento the vanes or floats. The vanes or floats have in fact a suitable length (Figs. 1 and 3) and are sufficiently prolonged from the point of inflection K for the guidance of the fluid to the ends of the channels to be completely assured.

7 and 8. Means employed for better utilizing the velocity of rotation at the ends ofthe vanes or floats and for delivering the fluid without eddies in the 7 receiving chamber.- These results are obtained by giving to each vane orfloat counting from about themiddle of its length, heights which successively in crease from the middle 0 Dto the endM-P. This special form given to the vane or float (see Figs. 2 and 4) permits the impelling velocity with which the vanes orfioats are animated tobe communicated not onlytothe current at the middle of thestream in each channel but to a number of parallel portions of said stream, whence it results that for a given volume delivered, a larger number of particles are impressed with the i-mpelling velocity of thewheel. Theprogressive increase in height given to the vane or float in the part 0 D ,P M moreover, allows the fluid to be delivered both to the centerand the periphery of the receiving chamber, whichdelivery tends to avoid eddies-thereinand-rte equalize the velocity of flow. On the other hand as the sections of thechannelsincrease progressively from. G D to MP, it results in accordance with what was said before. in section 3 on the form of channels with converging walls at the entering portions thereof that one of the characteristics of the new andimproved ventilator is to have convergingdiverging curvilinear channels, obtained by giving to each vane or float successivelydecreasing and increasing heights, the said converging diverging channels permitting a stream which fills the section to .be obtained throughout the length and in which consequently all eddies are avoided.

9. Diminution ofshoolcof the fluid flowing from the channels into the receiving chamber.-The essential condition foravoiding the shock of the streams from the channels and that flowing in the receivingch'amber is to give the same direction to both streams. It

is necessary then that the direction of the fluid atthe ends of the channels shouldnot be opposed to that of the stream inthe; receiving chamber, as isthe case inventilators in which the vanes or floats are inclined in.

the opposite direction to their rotation, but that they should be as nearly as possible parallel. The curvature of the vanes or floats in a ventilator with eccentric or concentric receiving chamber ought to be in the direction of the rotation of the wheel. This has been done in the new or improved apparatus by diminishing still more, as compared with ventilators in use with a flow of relatively constant velocity, the angle of the final portion of the vane or float to the tangent at the ex terior circumference of the wheel.

10. Reducing the friction in the receiving chamber-This friction may be due to two difierent causes. namely, to a perimeter having an extent of surface excessively great as compared with the section which it circumscribes, or to the approach of the wall of the receiving chamber on which the fluid from the channels is projected, too near the wheel. The double difficulty has been overcome in the new or improved apparatus by giving to the receiving chambers of blowers or aspirators of small diameters a circular section, which presents as is known the minimum of perimeter for a given section, and to the receiving chambers of blowing or aspirating and blowing apparatus of large diameters, such as the mine ventilators shown in Figs. 3 and 4, a form as near square as may be, so disposed as to remove from the vanes or floats the wall whose presence tends to give rise to the shocks.

Description of apparatus-The wheel comprises a circular disk of sheet steel M M fixed to a hub Q keyed on the arbor of rotation B. On. this disk are fixed say twenty-four to thirty more or less, vanes or floats of sheet steel. These vanes or floats each of simple curvature and conforming each to the fraction of a developable surface, conical or cylindro-conical for example, are bent forward near the crown in the manner to cut this at an angle of from forty to thirty degrees. The wheel is provided at its center with a sort of conical deflector S of spun brass or copper, fixed at its apex on the arbor of the wheel and at its base on the disk at the beginning of the vanes or floats. The wheel is mounted on the arbor of rotation R, which rests on two standards T T placed symmetrically on opposite sides of the wheel and it turns in an envelope U forming the receiving chamber. The position of the wheel with reference to the receiving chamber is such that its exterior circumference is tangent to the inner plane of the receiving chamber without overpassing the same at any point. The arbor R of the ventilator wheel. diminishes in cross section from the point of its attachment to the wheel, toits extremities in a manner to present a solid of equal resistance to torsion and flection. It can be driven by symmetrically placed pulleys, which arrangement has the advantage of reducing the section of the arbor in the bearing and of thus uniting, in a construction rationally balanced and avoiding all false load, the minimum of friction of the parts in contact. Each inlet of the ventilator is formed by a sort of hollow converging guide A on the cheeksof the ventilator. In the mine ventilator of which the rectangular pipe is surrounded by a diffuser, the eduction orifice can take any direction about the aspiration shells fastened to the cheeks of the ventilator. It snffices simply to change the position of the bolts whichfasten these pieces together. In the blowing ventilator in like manner any direction can be given the eduction pipe.

The envelope of the ventilator is provided to the end with ears or m, which may be in any position about the ventilator inlet. The lower parts of these cars in contact with the soles X X of the standards present circular forms so that their adjustment in the said soles centers and fixes as wellthe direction and distance of the standards with reference to the arbor of the ventilator.

I claim as my invention or discovery- 1. A ventilator having between the vanes or floats channels with converging-diverging walls, substantially as described.

2. A ventilator havinginwardly extending cheeks and vanes or floats increasing in height from the middle toward the channel entrances and exits corresponding with the cheeks, substantially as described.

3. A ventilator having vanes of developable form, the portion nearest the exit of the fluid being part of a cylindrical surface and that nearest the entrance being part of the surface of an oblique cone, the edge of the vane having an inclination at its difierent points varying with their distance from the center of the wheel, substantially as described.

at. A ventilator having vanes or floats bent to conform in part to a cylindrical surface and in part to the surface of an oblique cone, said vanes diminishing in height from the entrance inward and then increasing to the point of exit, substantially as described.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

CHARLES GEORGES HEKSGHER.

Witnesses:

J EAN VIoTon BABTAMEY, DAVID T. S. FULLER. 

